1. Field of the Invention
The present invention relates to a method for producing a wiring harness.
2. Description of the Related Art
A wiring harness disclosed in Patent Document 1 listed below includes: three high-voltage electrical power lines; and three metallic protection pipes respectively receiving thee high-voltage electrical power lines. The high-voltage electrical power lines connect a motor mounted at a front side of a vehicle to an inverter mounted at a middle or rear side of the vehicle.
The wiring harness is arranged via an under floor of a vehicle body disposed at an outside of a vehicle body frame. Therefore, the metallic protection pipe protects the high-voltage electrical power line from a jumping stone or spattering water. Further, the metallic protection pipe has rigidity to prevent a slack of the high-voltage electrical power line, and works as an electromagnetic shield because of a metallic body.
The wiring harness is produced by firstly inserting three high-voltage electrical power lines into three straight metallic protection pipes respectively, and by bending the metallic protection pipes along wiring routes of the wiring harness at the under floor of the vehicle. After the wiring harness is produced as described above in a factory of a harness maker, the wiring harness is delivered to an assembly factory of a car maker, and assembled on a predetermined position of a vehicle, thereby an arrangement of the wiring harness is finished.
Incidentally, because the wiring harness is arranged through the under floor, and arranged penetrating a vehicle body panel toward an inside of the vehicle, waterproof treatment is needed at the vehicle body panel. Regarding the waterproof treatment, for example, Patent Document 2 discloses one technique. Namely, a waterproof structure is known in which a through hole is formed on the vehicle body panel, and a grommet is attached to the through hole.
Patent Document 2 discloses two examples. In one example, the number of openings corresponds to the number of electric wires. In the other example, gelled polymer is used. In the former example, wires are extracted through the openings respectively. In the latter example, the gelled polymer is wrapped around tied wires, and then, the tied wires are inserted into the grommet.
[Patent Document 1] Japanese Published Patent Application No. 2004-224156
[Patent Document 2] Japanese Published Patent Application No. H11-178164
Regarding the wiring harness disclosed in Patent Document 1, firstly, the high-voltage electrical power line is inserted into the straight metallic protection pipe, then this operation is repeated in the number of the high-voltage electrical power lines, and then, the metallic protection pipes are bent. Therefore, there is a problem that productivity is relatively low. Further, because using the metallic pipes, there is a problem that handling ability is low not only during the wiring harness production but also after the wiring harness production.
On the other hand, regarding the waterproof structure disclosed in Patent Document 2, it is necessary to draw-the electric wire through the grommet one by one, or to wrap the gelled polymer around the tied wires, and insert the tied wire into the grommet. Therefore, there is a problem that wiring workability is low in both cases. Consequently, when the wiring harness is arranged in the under floor, waterproof treatment affects the wiring workability.
Accordingly, an object of the present invention is to provide a method for producing a wiring harness to improve productivity, handling ability, and wiring workability.